Fan



Dec. 1, 1964 F. R. GRuNl-:R ETAL 359335 FAN Filed March 6, 1963 2 Sheets-Sheet 1 14 f 19 lmumnuuml IN VEN TORJ ATTORNEYS Dec. 1, 1964 v F. R. GRUNER ETAL 3,159,335

FAN

Filed Maron e, 1963 2 sheets-sheet 2 ATTORNEYS UnitedStates Patent O Frederick il. Gruner, Moline, and llioy lll. Sehwegler, Roch island, ill., assignors to Anietelr, luc., New York, NX., a corporation of Delaware Filed Mai'. d, lll/63, Ser. No. 263,143 ll fl'llaims. dCi. 23d-117;

This invention relates to fans for exhaust systems and particularly to an improved double duct or dual duct fan assembly capable of withstanding exhaust gases at elevated temperatures.

Double duct fans are employed in exhaust systems for furnaces and the like, and usually comprise a housing forming part of a stack and having parallel paths of tlow on each side of a central portion that is open to the atmosphere and in which portion a fan motor is mounted.

lt often happens that during furnace charging periods,

-. llames from the furnace extend into the stach and up through the double duct fan assembly. This causes excessive heating of `the fan motor bearings, windings and other parts of the motor, tending to decrease its useful lite. f

The principal object of the invention isy to' provide a double duct fan arrangement that will be capable of withstanding high temperatures.

Another object of the invention is to provide such a fan in which atmospheric air is forcibly circulated between the motor and fan housing.

Still another object of the invention is to provide such a y fan in which a radiation shield is provided between the motor and housing.

Still another object of the invention is to provide such a fan assembly in which the motor shaft supports, in addition to the main fan, an auxiliary fan for forcing atmospheric air through the space between the radiation shield and the housing.

A double duct fan assembly may comprise a main cylindrical housing having truste-conical sections at each end so that it can be connected into a stack for a furnace or other exhaust'system. The cylindrical portion may be provided with diametrically aligned, elliptical openings for receiving a hollow auxiliary housing extending through the cylindrical portion. The periphery of the auxiliary housing may be welded or otherwise securely fastened to the peripheral edges of the elliptical openings in the cylindrical housing. A plate may be mounted within the hollow auxiliary housing for supporting a fan motor with the axis of its output shaft lying along the longitudinal axis or the main housing.

ln one aspect oi' the invention, a radiation shield may comprise two hollow, elliptical-shaped sections of less dimensions :than those of the auxiliary housing. The walls of one side of the elliptical-shaped sections maybe slotted so that when the sections are brought togethenthe slots receive the plate for the fan motor. v Supporting clips may Instill another aspect of the invention, the output shaft of the motor may also support auxiliary fan means between thev radiation shield and the auxiliary elliptical housing 'member'for circulating outside air between the radiation shield andthe auxiliary housing member.

In stillk another aspect of the invention, the auxiliary Y point adjacent to the ian 26.

lice i g fan means may include blades arranged in a backward curved manner relative to the rotation of the fan and the radiation shield adjacent the auxiliary fan means may be provided with a dow controlling flange adjacent the auxiliary fan.

in still another aspect o the invention, baille means may be provided within the main housing surrounding the motor shaft extension leading from the auxiliary housing member and the main fan.

The above, other objects and novel features of the invention will become apparent from the following specification and accompanying drawings which are merely exemplary.

in the drawings:

llG. l is an end View of a double duct exhaust ian to which the principles of the invention have been applied;

FlG. 2 is an elevational View of the fan shown in FlG. 1;

FlG. 3 is an exploded perspective view of the radiationy guard and motor which it is designed to protect;

FIG. 4 is a plan view of kthe auxiliary fan forming part of the invention;

FiG. 5 is a View looking in the direction ofthe arrows along line 5 5 of FIG. 4; and

FIG. 6 is a View of a modified form of the invention,

Referring to the drawings and particularly to FIGS. 1 and 2, the principles ofthe invention are shown as applied to a double duct fan including a main hollow, cylindrical housing l@ having ilanges 11 and 12 at each end thereof that are connected to mating iianges on frusto-conical end portions l andk 14. The` ends of the frus-to-conical portions 13, ld may include flanges 15 and 16 for attachment to stach sections of an exhaust system.

The assembled main housing with its truste-conical end sections may be provided vwith diametrically opposed elliptical openings Il? and 18 adapted to receive an elliptical housing member 19 that extends along a diameter 'of' housing lll completely through thesame. The edges of the elliptical openings 17, 18 may be welded or otherwise hermetically sealed to the periphery of the elliptical mernber 19. The housing, therefore, comprises parallel spaced passages extending longitudinally through it for the passage of gases, and a central transverse passage Z0 through the housing that is open at each end to the atmosphere.

A plate 21 may be fixedly mounted within the ypassage Zti, and it may support an electric motor 22 with the axis of its output shaft 23 .ying along the longitudinal centerline of the housing lil'. The plate 21 may be welded to the housing member 19 or otherwise securelyinounted within the passage 2li. The motor 22 may be bolted to plate i9 by bolts 2d.

The shaft 235 may have fixed to it an extension 25 that extends to a point adjant the flange 15 of .the section i3. A fan 2d may be lixed to shaft extension 2.5, and it may be of a diameter substantially equal to that kot the end of 'section yi3 adjacent ilange 15, making a slight clearance with said section at that point. prevent the hotexhaust gases from attacking the extension 2d, baffle means 2'? within section'lll may surround extensionfa" and extend from housing member 17 toa A radiation shield 28 may be mounted within the pasthat conform generally to the form of the sidewalls of thehousing member 19! y'I op and bottom plates 313 and 3d larecomie'cted to thefside walls 31 and 32, and each plate 33 provided with a semicircular recess 35 surrounded by a flange 36 having a smooth curved portion 37.y

In order to The side Walls 31 of sections 29 and 3@ may be provided with aligned slots 3@ and 39 of a width to receive the plate 2i within passage 20. Accordingly, when sections 29, Sti are brought together within passage Zd, their edges are permitted to abut each other with plate 2li passing through one side of the radiation shield 2b, and the half-circular openings 35 close about the extensionZi to such an extent as to provide an annular passage di) (FIG. 2) between the abutting ilanges 36 and the extension 25.

Clips 41 may be permanently attached to the opposite ends of sections 29 andstti, and they are adapted to be connected to the opposite ends of housing member t9. The clips 41 are formed in a manner to space the radiation shield 28 inwardly of the housing member i9 in order to provide a passage 42 between the shield 28 and housing member 19 for the passage of air therethrough.

The extension 25 is adapted to have fixed to it an auxiliary fan 43 between the plates 33 of shield 28 and housing member i9. Referring to FIG. 4, the auxiliary fan 43 may comprise two half-circular disks 44- and having upturned flanged portions 46, 47 that can be bolted together by bolts 48. Blades 49 may comprise angle members arranged in a backward inclined position relative to the direction of rotation of said fan and at equal intervals about the disks lid, 45. Batlle members Sti, Si may be mounted on plates 33 of shield 2t? on each side of the fan i3 for a purpose to be described.

Referring to FIG. 2, energization of the motor 22 rotates fan 26, causing air to be sucked or passed through the two parallel passages within housing iti on each side of the transverse through passage 2d, thence past the battle `27 and through tan 2e. At the same time, fan 43 sucks outside air in through the two open ends of transverse passage 2t) between motor 22 and shield 28, thence through annular passage 40, past flow-control contoured throat flange 37, thence radially outwardly along fan blades '49. Batlles 5i), Sil direct the air around radiation shield 28, between it and housing member 19, thence outwardly from passage 2t) near the bottom thereof as viewed in FIG. 2. Accordingly, a constant flow lof outside air is forcibly circuiated between the radiation shield 28 and the housing member i9 to maintain the temperature of the motor 22, its bearings, and its windings at a `safe value regardless of the temperature of the exhaust gases passing through housing it).

Referring to FIG. 6, the principles of the invention are shown as applied to a modified form ot fan in which the motor 22 is provided with a drive shaft 52 that extends from the end of motor 22 opposite that from which shaft 23 extends. Shaft 52 may also be provided with an extension 53 surrounded by -a battle 54 similar to extension 25 and baffle 27 previously described. The extension 53 may xedly support a fan 5S adjacent the flange t6 in the same way that fan 26 is mounted on extension 25 adjacent flange 15.

An additional auxiliary tan 56, similar to tan 43, may be fixed to extension 5.3 between the lower end of shield 2.8 and the housing member i9. The shield 2d is also provided with flanged iiow control passages 37 at the two ends of the shield.` ln the embodiment of FIG. 6, energizing motor 22 causes fans 55 and Ze to Y suck or transport the air through the parallel spaced passages within housing iti while fans i3 and Se suck air from the passage Zit, through tlow control tiange portions 37, thence radially outwardly and downwardly and upwardly, successively, within passage i2 between shield 23 and member i9, thence transversely of housing iti to the atmosphere.

Although the various features of the double duct fan have been shown and described in detail to fully disclose two embodiments of the invention, it will be evident that changes may be made in such details and certain features may be used without others without departing from the principles of the invention.

What is claimed is:

l. A fan comprising in combination, a main housing member; an auxiliary housing member extending transversely through said main housing member and separating the main housing member into two parallel passageways, one on each side of said auxiliary housing member, and forming a transverse passage through said main housing member, said passage being open lat both ends to the atmosphere; a motor mounted in said transverse passage having output shaft means extending through the wall of said auxiliary housing member into said main housing member; main tan means connected to said output shaft means within said main housing member for sticking air through said spaced parallel passageways within said main housing member; a radiation shield Within said transverse passage between said motor and said auxiliary housing member; and means for causing outside air to circulate over said motor and through the space between said radiation shield and said auxiliary housing member.

2. A fan comprising in combination, a main housing member; an auxiliary housing member extending transversely through said main housing member and separating the main housing member into two parallel passageways, one on each side of said auxiliary housing member, and forming a transverse passage through said main housing member, said passage being open at both ends to the atmophere; a motor mounted in said transverse passage having output shaft means extending through the wall of said auxiliary housing member into said main housing member; main fan means connected to said output shaft means within said main housing member for sucking air through said spaced parallel passageways within said main housing member; a radiation shield within said transverse passage between said motor and said auxiliary housing member; and auxiliary fan means connected to said output shaft means for sucking outside air through said transverse passage, over said motor and through the space between said radiation shield and said auxiliary housing member.

3. A fan comprising in combination, a main housing member; an auxiliary housing member extending transversely through said main housing member and separating the main housing member into two parallel passageways, one on each side of said auxiliary housing member, and forming a transverse passage through said main housing member, said passage being open at both ends to the atmosphere; a motor mounted in said transverse passage having output shaft means extending through the wall of said auxiliary housing member into said main housing member; main fan means connected to said output shaft means within said main housing member for sucking air through said spaced parallel passageways Within said main housing member; baille means within said main housing member surrounding said output shaft means between said auxiliary housing member and said main fan means; a radiation shield within said transverse passage between said motor and said auxiliary housing member; and means for causing outside air to circulate over said motor and through the space between said radiation shield and said auxiliary housing member.

LA fan comprising in combination, a main housing member; an auxiliary housing member extending transversely through said main housing member and separating the main housing member into two parallel passageways, one on each side of said auxiliary housing member, and forming a transverse passage through said main housing member, said passage being open at both ends to the atmosphere; a motor mounted in said transverse passage having output shaft means extending through the wall of said auxiliary housing member into said main housing member; main fan means connected to said output shaft means within said main housing member for sucking air through said space parallel passageways within said main housing member; baflie means within said main housing member surrounding said output shaft means between said auxiliary housing member and said main fan means; a radiation shield within said transverse passage between said motor and said auxiliary housing member; and auxiliary fan means connected to said output shaft means for sucking outside air through said transverse passage, over said motor and through the space between said radiation shield and said auxiliary housing member.

5. A fan comprising in combination, a mainl housing member; an auxiliary housing member extending transversely through said main housing member and separating the main housing member into two parallel passage- Ways, oneoneach side of said auxiliary housing member, and forming a transverse passage through said main housing member, said passage being open at both ends to the atmosphere; a motor mounted in said transverse passage having output shaft means extending through the Wall of said auxiliary housing member into said main housing member; main fan means connected to said output shaft means within said main housing member for sucking air through said spaced parallelvpassageways Within said main housing member; a radiation shield within said transverse passage between 'said motor and said auxiliary housing member; auxiliary fan means connected to said output shaft means for sucking outside air through said transverse passage, over said motor and through the space'between y said radiation shield and said auxiliary housing member; and baille means on each side of said auxiliary fan means.

. v6. A fan comprising in combination, a main housing member; an auxiliary housing member extending transversely through said main housing member and separating the main housing member into twov parallel passageways,

one on each'side of said auxiliar yhousin member and f forming a transverse passage through said main housing member, said passage being open at both ends to the atmosphere; a verticallypdisposed plate mounted r'within said transverse passage; a motor mounted on said plate and including output shaft means extending through the wall of said auxiliary housing member into said main housing member; main fan means connected to said output shaft means within said main housing member for sucking air through said spaced parallel passageways within said main yhousing member; a radiation shield within said transversey passage, said shield 'comprising aligned complementary sections adapted to be held in end abutting relation and having aligned spaced slots adapted to receive said plate, said abutting ends alsoincluding flanged semicircular recess adapted when said sections are in abutting relation to encircle said output shaft means; and means for causing outside air to circulateover said motor and through the spacey between said radiation shield and said auxiliary housing member. y

7. A fan comprising in combination, a main housing member; an auxiliary housingmernber extending transversely through said main housing member and separating'the main housing member into two parallel passageways, one yon each side of said auxiliary housing member,

, and forminga transverse passage through said main housing member, said passage being open at both ends to the atmosphere; a vertically disposed. plate mounted within said transverse passage; a motorrnounted on said plate and including output shaft means extending through the Wall of said `auxiliary housing member into said main fan means connected to said output shaft means for'suclring outside air through said transverse passage, overy said motor and through the space between said radiation shield and said auxiliary housing member.

8. A han comprising in combination, a main housing member; an auxiliary housing member extending transversely through said main housing member and separating the main housing member into two parallel passageways, one on each side of said auxiliary housing member, and forming a transverse passage through said main housing member, said passage being open at bothends to the atmosphere; a vertically disposed plate mounted within saidtransverse passage; a motor mounted on said plate and including output shaft means,- extending through the wall of said auxiliary housing member into said main housing member; main fan means connected to said output shaft means within said main housing member. for sucking `air through said spaced paral el passage'ways within said main housing member; baiiie means within said main housing member' surrounding said output shaft means between said auxiliary housing member and said main fan means; a radiation shield within said transverse passage, said shield comprising aligned complementary sections adapted to be held in end abutting relation and having aligned spaced slots adapted to receive said plate, saidabutting ends also including hanged semicircular recesses adapted when said sections are in abutting krelation to encircle said output shaft means; and means for causing outside air to circulate over said motor and through the space between said radiation shield and said auxiliary housing member. i

9. A fan comprising in combination, a mainhousing member; an auxiliary housing member extending transversely through said main housing member and separating the'main housing member into two parallel passageways, one on each side of said auxiliary housing member, and forming a transverse passage through said main housing member, saidpassage being open at both ends to the atmosphere; vertically disposed plate mounted within said transverse passage; a motor mounted on said plate and including output shaft means extending through the wall of said auxiliary housing member into said matin housing member; main fan means connected to said output shaft within said main housing member for sucking air through said spaced parallel passageways within said main housing member; bathe means within said main housing member surrounding said output shaft means between said auxiliary housing member and said main fan means; a radiation shield within said transverse passage,

said shield comprising `aligned complementary sections adapted toy beheld in end abutting relation and having aligned spaced slots adapted to receive said plate, said abutting ends also including flanged semiicircular recesses adapted `when said sections are in abutting relation to encircle said output shaft means; and auxiliary fan means connected to said output shaft means for sucking outside air through said transverse passage, over said motor and throughthe space between said radiation shield and said auxiliary housing member.

l0. A fan comprising in combination, a mainhousing member; an auxiliary housing,memberextending transversely through said main housing member and separatin0 the'rnainhousinfr member into two arallel bassa eways, one on each side of said auxiliary housing member,

and forming a transverse passage through said main housing member, saidpassage being open atfboth ends to the atmosphere; a vertically disposed plate mountedk within said transverse passage; a motor mounted on said plate* ceive said plate, said abutting ends also including flanged semicircular recesses adapted when said sections are in abutting relation to encircle said output shaft means; auxiliary -fan means connected to said output shaft means for sucking outside air through said transverse passage, over said motor and through the space between said radiation shield and said auxiliary housing member; and baille means on each side of said auxiliary fan means.

11. A fan comprising in combination, a main housing member; -an auxiliary housing member extending transversely through said main housing member and separating the main housing member into two parallel passageways, one on each side of said auxiliary housing member, and forming a transverse passage through said main housing member, said pass-age being open at both ends to the atmosphere; a motor mounted in said transverse passage having an output shaft extending from each end thereof through the walls of said auxiliary housing men ber in opposite directions and into said main housing member; separate main fans connected to each of said output shafts within said main housing member and arranged to suck air in one direction through said spaced parallel passages within said main housing member; a radiation shield within said transverse passage between said moto-r and said auxiliary housing member; and means for causing outside air toy circulate over said motor and through the space between said radiation shield and said auxiliary housing member.

12. A fan comprising in combination, a main housing member; an auxiliary housing member extending transversely through said main housing member and separating the main 'housing member into two parallel passageways, one on each side of said auxiliary housing member, and forming a transverse passage through said main housing member, said passage being open at both ends to the atmosphere; a motor mounted in said transverse passage having an output shaft extending from each end thereof through the walls of said auxiliary housing member in opposite directions and into said main housing member; separate main fans connected to each of said output shafts within said main housing member and arranged to suck air in one direction through said spaced parallel passages within said main housing member; a radiation shield within said transverse passage between said motor and said auxiliary housing member; and separate auxiliary fan means connected to each of said output shafts for sucking outside air through said transverse passage, over said motor and through the space between said radiation shield and said auxiliary housing member.

13. A fan comprising in combination, a main housing member; an auxiliary housing member extending transversely through said main housing member and separating the main housing member into two parallel passageways, one on each side of said auxiliary housing member, and forming a transverse passage through said main housing member, said passage being open at both ends to the atmosphere; a motor mounted in said transverse passage having an output shaft extending from each end thereof through the walls of said auxiliary housing member in opposite directions and into said main housing member; separate main fans connected to each of said output shafts within said main housing member and arranged to suck air in one direction through said spaced parallel passages within said main housing member; baille means within said main housing member surrounding said output shaft means between said auxiliary housing member and said main fan means; a radiation shield within said transverse passage between said motor and said auxiliary housing member; and means for causing outside air to circulate over said motor and through the space between said radiation shield and said auxiliary housing member.

14. A fan comprising in combination, a main housing member; an auxiliary housing member zextending transversely through said main housing member and separating the main housing member into two parallel passageways, one on each side of said auxiliary housing member, and formi-ng a transverse passage through said main housing member, said passage being open at both ends to the atmosphere; a motor mounted in said transverse passage having an output shaft extending from each end thereof through the walls of said auxiliary housing member in opposite directions and into said main housing member; separate main fans connected to each of said output shafts within said main housing member and arranged to suck air in one direction through said spaced parallel passages within said main housing member; baille means within said main housing member surrounding said output shaft means between said auxiliary housing member and said main fan means; a radiation shield within said transverse passage between said motor and said auxiliary housing member; and separate auxiliary fan means connected to each of said output shafts for sucking Outside air through said transverse passage, over said motor and through the space between said radiation shield and said auxiliary housing member.

l5. A fan comprising in combination, a main housing member; an auxiliary housing member extending transversely through said main housing member and separating the main housing member into two parallel passageways, one on each side of said auxiliary housing member, and forming a transverse passage through said main housing member, said passage being open at both ends to the atmosphere; a motor mounted in said transverse passage having an output shaft extending from each end thereof through the walls of said auxiliary housing member in opposite directions and into said main housing member; separate main fans connected to each of said output shafts within said main housing member and arranged to suck air in one direction through said spaced parallel passages within said main housing member; a radiation shield within said transverse passage between said motor and said auxiliary housing member; separate auxiliary fan means connected to each of said output shafts for sucking outside air through said transverse passage, over said motor and through the space between said radiation shield and said auxiliary housing member; and bafe means on each side of said auxiliary fan means.

16. A fan comprising in combination, a main housing member; an auxiliary housing member extending transversely through said main housing member and separating the main housing member i-nto two parallel passageways, one on each side of said auxiliary housing member, and forming a transverse passage through said main housing member, said passage being open at both end to the atmosphere; a vertically disposed plate mounted within said transverse passage; a motor mounted on said plate and including an output shaft extending from both ends of said motor, through the wall of said auxiliary housing member into said main housing member; separate main fans connected to the opposite ends of said ouput shaft within said main housing member, the blades of said fans being arranged to suck air in one direction through said spaced parallel passageways within said main housing member; a radiation shield within said transverse passage, said shield comprising aligned complementary sections adapted to be held in end abutting relation and having aligned spaced slots adapted to receive said plate, said abutting ends also including hanged semicircular recesses adapted when said sections are in abutting relation to encircle both `opposite extending portions of said output shaft; and means for causing outside air to circulate over said motor and through the space between said radiation shield and said auxiliary housing member.

17. A fan comprising in combination, a main housing member; an auxiliary housing member extending transversely through said main housing member and separating the main housing member :into two parallel passageways, one on each side of said auxiliary housing member, and forming a transverse passage through said main housing member, said passage being open at both ends to the atmosphere; Va vertically disposed plate mounted Within said transverse passage; a motor mounted on said plate and including an output shaft extending from both ends of said motor; through the Wall of said auxiliary housing member into said main housing member; separate main fans connected to the opposite ends of said output shaft within said main housing member, the blades of said fans being arranged to suck air in one direction through said spaced parallel passageways within said main housing member; a radiation shield within said transverse passage, said shield comprising aligned complementary sections adapted to be held in end abutting relation and having aligned spaced slots adapted to receive said plate, said abutting ends also including anged semicircular recesses adapted when said sections are in abutting relation to encircle both opposite extending portions of said output shaft; and separate auxiliary fan means connected to the opposite extending portions of said output shaft for sucking outside air through said transverse passage, over said motor and through the space between said radiation shield and said auxiliary housing member.

References Cited in the file of this patent UNITED STATES PATENTS 1,702,632 Bothezat Feb. 19, 1927 2,419,962 McLarty May 6, 1947 2,465,042 Schlenker et al Mar. 22, 1949 Carson Oct. 3l, 1950 

1. A FAN COMPRISING IN COMBINATION, A MAIN HOUSING MEMBER; AN AUXILIARY HOUSING MEMBER EXTENDING TRANSVERSELY THROUGH SAID MAIN HOUSING MEMBER AND SEPARATING THE MAIN HOUSING MEMBER INTO TWO PARALLEL PASSAGEWAYS, ONE ON EACH SIDE OF SAID AUXILIARY HOUSING MEMBER, AND FORMING A TRANSVERSE PASSAGE THROUGH SAID MAIN HOUSING MEMBER, SAID PASSAGE BEING OPEN AT BOTH ENDS TO THE ATMOSPHERE; A MOTOR MOUNTED IN SAID TRANSVERSE PASSAGE HAVING OUTPUT SHAFT MEANS EXTENDING THROUGH THE WALL OF SAID AUXILIARY HOUSING MEMBER INTO SAID MAIN HOUSING MEMBER; MAIN FAN MEANS CONNECTED TO SAID OUTPUT SHAFT MEANS WITHIN SAID MAIN HOUSING MEMBER FOR SUCKING AIR THROUGH SAID SPACED PARALLEL PASSAGEWAYS WITHIN SAID MAIN HOUSING MEMBER; A RADIATION SHIELD WITHIN SAID TRANSVERSE PASSAGE BETWEEN SAID MOTOR AND SAID AUXILIARY HOUSING MEMBER; AND MEANS FOR CAUSING OUTSIDE AIR TO CIRCULATE OVER SAID MOTOR AND THROUGH THE SPACE BETWEEN SAID RADIATION SHIELD AND SAID AUXILIARY HOUSING MEMBER 